Vehicles include various types of lamp assemblies that include lenses. Lamp assemblies can include headlamps, tail lamps, and other types of lamp assemblies. Lamp assemblies include a lens covering a light source. The lens is at least partially transparent to permit light from the light source to emanate from the lamp assembly through the lens.
Some lenses include a polycarbonate material coated with a silicon hardcoat material. The hardcoat is exposed and helps to prevent abrasion of the lens. After sufficient exposure to ultraviolet radiation, such lenses can become hazy and less transparent. Increased exposure to ultraviolet radiation can increase the hazing.